One common and effective commercially used disinfecting agent for treatment of soil is methyl bromide. Methyl bromide effectively destroys living cells once methyl bromide is transported across the cell wall. However, methyl bromide is being phased out of use due to its deleterious effect on the ozone layer and due to its human health hazards. Thus a substitute for methyl bromide is urgently needed.
Ozone in aqueous solutions has been used for inhibition or reduction of biological life forms such as molds, fungi, bacteria, algae, in numerous applications including swimming pools, potable water, bottled water, aquaria, fish hatcheries, and cooling towers. In the gas phase, ozone has been used primarily in the food processing industries for treatment of, for example, fish, grains, delicate vegetables, and processed foods. Gaseous ozone has also been used as a sanitizing agent for operating rooms, animal containment facilities, and air conditioning and heating ventilation systems and for deodorization in municipal waste treatment plants.
However, ozone has not reportedly been used to sanitize the soil in a field. Ozone in aqueous solutions has the drawback of slow dispersion of water into and through the soil of a field. Furthermore, aqueous ozone solutions suffer from rapid breakdown of ozone and the resultant difficulty in maintaining sufficiently high concentrations of ozone in the water in the soil. Ozone in aqueous solutions has a half life on the order of minutes in ambient conditions.
Although gaseous ozone has a half life on the order of hours (up to 20 hours depending on ambient conditions), gaseous ozone has not been traditionally used to sanitize soil in a field. According to traditional thinking, if gaseous ozone were used for soil treatment, ozone would rapidly break down by dissolving in the water entrapped in the soil. It was also thought that gaseous ozone dispersion is inhibited by the compacted, compressed nature of soil in a field and that untoward emissions of ozone gas from the soil in a field into the atmosphere minimized ozone's effectiveness.